Prescribe Sub-Symptom Exercise for Adolescent Concussion R package PPCSexRx version 0.1.0 A clinical decision support system for sub-symptom threshold aerobic exercise (SSTAE) prescription in adolescents with persistent post-concussion symptoms (PPCS). Implements an evidence-based protocol derived from a systematic review of seven studies (Li, 2026; <doi:10.17605/osf.io/kvuf6>), encoding safety screening, Buffalo Concussion Treadmill Test (BCTT)-guided heart rate prescription, session-level progress tracking, and evidence disclosure using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework into an open-source tool for athletic trainers and clinicians. Designed to support implementation in resource-limited settings where BCTT equipment may be unavailable. GRADE certainty of evidence: LOW. For clinician use only; not a substitute for clinical judgement. Software Imports: graphics, utils Suggests: knitr, rmarkdown, testthat (>= 3.0.0) Guang Li <guangli@isu.edu> Comprehensive R Archive Network (CRAN) Guang Li [aut, cre] (ORCID: <https://orcid.org/0009-0004-2807-9029>) MIT + file LICENSE (https://CRAN.R-project.org/package=PPCSexRx/LICENSE) 2026-06-01 application/tgz https://CRAN.R-project.org/package=PPCSexRx doi:10.32614/CRAN.package.PPCSexRx